Slit seeders can be very hard to use at times. Make sure to read the manual on the proper height, because each machine can differ in depth settings. You should have minimum thatch brought up when doing seeding. If you do bring up any, you should be able to pick up most of it by hand. It the thatch is greater than 1/2 inch, then I suggest dethatching the lawn first.

My going rate for slit seeding is $28 per 1,000 sq ft. That is the labor and seed.